This invention relates to guidance systems for controlling missiles and more particularly relates to the use of radar equipment to provide the guidance commands. The use of radar transmitting equipment permits controlling a vehicle by the same means by which it is detected. The invention is concerned with providing two or more functions in one frequency band on a non-interfering basis with the result that precious frequency space will be available for other uses.
The idea of command guidance is not new. For example radio controlled missiles, drones, etc., are well known in the art. Likewise, the use of radar signals to provide command guidance is not new. The advantage of using radar signals for command guidance is that it is difficult for any enemy to know when guidance signals are being given or to know what the guidance commands are. By adding pulse to pulse frequency diversity and prf jitter to the radar signal, it becomes even more difficult for the enemy to deceive a missile guidance circuit or to know what part of the frequency spectrum to jam. Present guidance systems have a disadvantage in that they use either two completely separate systems which transmit two different types of signals or the two separate systems transmit signals at different frequencies thus using up a substantial portion of the frequency spectrum available. For example, one system uses pulse radar to guide the missile while using a CW illuminating radar to track the target while another system uses a doppler radar along with a pulse radar to provide guidance to the missile. These systems are necessarily complicated and expensive.